As is always a sign of a good component upgrade, the Zbox is responsible for changing my sleeping patterns... Usually it ends at about 2:30 - 3:30 am on the couch having slept for an hour or two....only to stay up and listen some more....

On the weekend I intend to swap the Zbox in and out.... however I think this is a winner....

All I can really say definitely right now is. . . it's a damned fine preamp for the price! Gets out of the way, offers precise control of volume, doesn't cloud or really add much of a signature of its own.

Amazing value for the price in that respect I feel.

I've introduced so many variables to the system along with it (another power cord, another tube and actually lots of tubes swapped in and out, two sets of interconnects now because I've gotten the Decware interconnects in place now, replacing my TARA Labs interconnects) that I really can't speak to how it may be "sweetening" cd playback. . . . It may be. It may be smoothening the top end a bit compared to directly into the Monoblock amps. I'll have to reconfigure and do direct comparisons at some point in the near future.

I'm definitely keeping mine, because it is nice to have a preamp and this is one fine preamp! Glad you are enjoying yours so much Grant!

Did I miss something along the way, I thought the Z-Box was a cathode follower-buffer with no gain and an attenuator (aka volume pot) on the input side, not a pre-AMPLIFIER. Nevertheless, they sure must sound nice, lowering all that nasty impedance and what not.

Yep. It's an attenuator not a pre-amp. That's why I chose CSP over Zbox because my CDP only outputs 2.2V which is not enough to fully take advantage of a Taboo I think. But the Zbox is a great choice if you have a high output source like Lon does.

Just wait a bit.... I 'think' it's starting to do nice things to the sound. ie. more detail, weight and distance between instruments.... it does roll the highs a bit methinks however it is emenently listenable, or not as the sleeping seems to attest....

Ever since I have moved to a cd source, I've not needed gain in a preamp, I've just needed a volume attenuation. . . .In that sense this is a preamp, and a darned good one. And cheaper than a CSP. . . and simpler.

Corey I have NEVER been happy with a JJ input tube before, and as I have a number of Mullards and other NOS tubes to use, I'm not going to bother with the JJ except as a last resort. (I'm picky about input tubes and have a lot to choose from; old guitar amp habits die hard). I am positive that the "liquidity" in the machine is not due to the JJ tube.

The point I guess I haven't made too clear is that I was enjoying liquidity (whatever that really is) before the Zbox with the tubed output of the DEC685 and it's major benefit to me is that it serves very well as a simple preamp.

I sense you are not getting the results others are getting in that you can't seem to notice anything out of the Box besides volume control.Deckert can hear and you should at least check out what he wanted to bring into your room with the stock component. It wouldn't be shipped if it didn't sound good. Every circuit is different and this one might shine with a JJ.

Deckert writes:

The ZBox tube heater circuit operates the dual 6.3 volt heaters in the tube at around 3 volts each. This reduces the efficiency of the tube, at the same time much of the pollution in the signal (that I refer to as "stress") is filtered off.

Corey, Steve ships with tubes that a person can buy new with no hunting and searching, that's his purpose there. He even mentions quite clearly that the Zbox is designed for easy tube rolling.

I may try the JJ sometime but I'm in no hurry to, because I know I have better tubes. All the other JJ input tubes I've used have been mediocre compared to the Mullards I'm using. I'm using right now a Mullard 12AT7 that has been cryo'd and is a notch above anything else I've used. (You might even try experimenting with tubes in your DEC685 because the Ruby that was sent with that was one of the lamest input tubes I've ever used sonically; who knows, you may enjoy the sound of the tubed output with a better tube).

Not to belabor this but I just can't yet qualify what I hear because the machine is not but ten days in use and because I've introduced a lot of varialbles to the system along with it. I'm not going to just gush over this when at this time the main thing it is doing is allowing me a preamp. It may be doing a lot more but the fact of the matter is I was extremely happy with my system without the Zbox and I'm still extremely happy with my system, and the Zbox is not hurting the sound in any way. It may improve further, I'll note that fact if it does. But, unlike others perhaps, I bought this machine to act as an inexpensive but compatible preamp for my system, and it is indeed doing so far a smashing job for that purpose. You probably want a Zbox or want to hear about a Zbox improving digital playback. I feel I've already accomplished that with the DEC685 tubed output section. Maybe you should order one and see if it will work for you as a digital improver, either allowing you to use the excellent tubed outputs of your DEC685 or sweetening the sound of the (as far as I am concerned) inferior stock outputs.

Mull, if you read carefully above and on another thread or two, I mostly ordered this because I decided I would see what all this preamp fuss was about, and I didn't want to go the full hog route of a CSP, which was more expense, gobs of gain I don't at all need, and more tubes and hard for me to place in my rack.

I'm very happy with my DEC685 and I'm very happy with the Zbox as a preamp. It may be doing all those other digital cleansing mentioned, but between adding another little stand, footers, and a new Decware interconnect, it's hard for me to definitively say "yes, it's improving my digital playback." I'd have to take it all down and listen to the DEC685 alone again to definitively say that, and I'm not doing that for a few weeks when I feel everything is broken in and is humming along.

Steve's usual "hype" about the box (hey, it's not bragging if it's true?) made me seriously consider buying it, but it was the fact that I didn't have a preamp and veryoldcat and others are claiming that adding a preamp compared to going straight into an amp was so great what got me interested as well. The real person to watch for comments about digital improvement with the Zbox for my money is veryoldcat, who will have one very soon I believe. He has a CSP and he's ordered a Zbox!

I'll let others who bought the Zbox for digital cleansing comment on those aspects for now. And I'll just bow out and continue listening.

My zbox is supposed to arrive this coming Thursday (pretty exciting). I'll likely give it a week before making too many comments, and I'll attempt to make the impression as honest as possible.

If there IS a noticeable improvement, I'm likely to be very affected, as even the best cd's in a quality system have always had a bottom line of listener fatigue, for my ears. Perhaps this is due to the sheer amount of music I repeatedly listen to that is lengthy and challenging to the ear (ie, classical music and a good amount of 20th century classical music, at that). Add that to 25+ years of hearing vinyl prior to the advent of cd's.

From your comments, Lon, the zbox and dec685 flourish with Mullard 12ax7's which I think I have a few of those floating around. I haven't gotten around to trying them in the dec685, and only have the stock ruby 12au7 in it as a reference during its break in, which is now pretty well done. The Decware/Sony 685 is a mighty musical sounding box, even for vinyl-trained ears.

Yes, indeed, Lon. The CSP/se84cs combination did wonders for digital playback in my system, absolutely no doubt about it. I wasn't trying to over-sell it. It was just such a drastic improvement over going straight into the zen.

The gain of the CSP was necessary in my system, as my phono pre is JUST BARELY enough gain for the se84cs with the volume all the way up, but the se84cs definitely sounds its most musical with the volume backed off, for me, to around 80% or so, and the gain increased as needed from the pre.

I've come to greatly trust Steve Deckert's ears, and a short phone discussion convinced me the Zbox was worth a try to further relax the sound of redbook cd's, even if a Zbox-CSP-Zen chain is a slightly more complicated setup.

At the moment I'm into a major listening binge of Carloz Chavez's music. There is a lot of texture in his music that can really test one's tolerance for digital playback, even with superb quality recordings, as cd's go. If the zbox sprays a little more wd-40 on my redbook cd's, it'll be killer worth it! I don't expect it to be a magic bullet, necessarily, but any improvements to redbook playback will be very very welcome.

Karl, I know you'll have fun trying out the Zbox and you're quite adventurous to try one out when you already have a CSP; I'm pretty sure if I already had a preamp, and a CSP at that, I wouldn't have a Zbox!

I know what you mean about phono playback, and personally I'm really fond of analog tape in various forms and wish the days when you could buy prerecorded reel to reels for example as the standard were here. Ah. . . it's been a long time but that's the best audio I really remember: tubed reel to reel into tube amplification. If the stuff on my 10,000 cds and cdrs were on tape I'd be using a tape based system.

Anyway, re: tubes for Zbox: I was using Mullard 12AX7s but I experimented last weekend with a tube I found didn't quite work in the DEC685 for me, a cryo'd Mullard 12AT7 and found it was really nice in the Zbox, and so I ordered another one to see whether the same tube in the DEC685 as well would work well. That second tube came Thursday and I popped it in the DEC685 and so far I really like the combination. It sacrifices a little low end perhaps, at least so far in the breakin of everything new (new tube, new Decware Reference interconnects, new Zbox and new configuration of having a "preamp" in the system). But it makes up for it with reallly vivid and lively treble and an open midrange. With some speaker placement changes and some changing of the setting on my PS Audio Power Plant I'm getting quite realistic sound.

Here's the tube if anyone is interested. I know I'm not alone in using this tube on this board. Not really cheap, but then not really expensive for Mullards, and cryo'd too:

I'll probably roll with tubes I already have for a little while, but great to know where these are, as I will likely give them a try a little later on.

I know what you mean about analog tape with a tube driven recorder. That was a sound I heard a lot of growing up. No decay in fidelity such as when you get closer to the end of a record!

Thanks again for the tube link. By the way, do you notice a generic difference between the 12ax7/12au7/12at7 in either the zbox or the dec685, or does it more or less seem to depend on the characteristics of the individual tube (and not so much whether it's an ax7, au7 or at7)?

I do hear family resemblance in the tube type, and then distinct differences in the brand. The lowest output in my experience is the 12AU7 type, a sound that for me may be too tame and mellow. The 12AX7 types are richer, creamier and with more gain. All those that I have are from my 1959 EICO though, and I know they have MILES on them. . . . I haven't any new tubes of this type on hand that are of any comparable sound. . . I bet these Mullards were giant-killers new. The 12AT7 type has been rather tart and tight in the DEC685 and no Zbox, but I'm enjoying it in the Zbox now and also in the DEC685. . . so far it's a good combo though I miss a bit of "richness" that may come in as things season. . . who knows.

So far with my experimentation I like the same tube type in both DEC685 and Zbox at one time, though that may be quite a different situation in another system. It's so wild how varied and vast the differences can be in this hobby.

Well, off to bed so I can wake up really early and get a few hours listening in before the world and wife awake!

Well I'v done a bit more swapping and for the most part my initial impressions have crystalized even more. There is a 'certain' reduction in the quickness and attack from the CS. The amp will put most anything to shame in terms of sheer light footedness and agility with music. However, the Zbox compensates with a sweeter sound, more presence and definition. Ie, there is more 'oomph' with instruments that makes the CS sound fuller and richer.

Soundstage is enhanced and I like the 'slightly' forward presentation. As I have the my input cables running directly into the non potted inputs at full volume, there is a lot of hum but it's neglegible when running anything musical through it.

I do feel that a lot is gained in the music though some benefit is lost. I still like the Zbox though and think it was a good purchase for the enhancements it makes to the sound.

For me, anything that helps to overcome the aural stress of digital playback (ie, an increase in musicality) is deadly worth it.

The immediate quickness and transparent zinginess of the zen without a preamp or buffer is pretty cool, but if you've listened for hours, the zen amp without preamp or buffer can be very edgy/fatiguing over the long haul, particularly with a cdp source.

The CSP pre has been very helpful in my system with cd sources, and hopefully the zbox will increase that even more.

I'm kind of hooked on vinyl for listenability and have a lot of records; but hey, I have more than a thousand cd's of incredible performances of incredible music that don't exist on vinyl that I'd like to sound better. If not perfect, the musicality needs to be increased. I'll gladly give up an inch of quickness and transparence for a mile of listenability with digital sources.

Okay Corey, I listened to the stock outputs, then to the Zbox added between the Dec 685 and the Monoblocks.

It does improve the sound of the stock inputs, everything is improved a little bit. I didn't listen long enough to make a lot of cool comments on how it sounds.

I will say this though: for me the tubed output of the Dec 685 straight into the Monoblocks sounds better still by a big margin than the Zbox and the stock outputs. And the Zbox after the tubed output stage into the Monoblocks sounds better, though I am still undecided whether the tubed output and Zbox is "better" than the tubed output straight in without Zbox. Both have different sounds, there are slight advantages to each.

I was releived to take the stock outputs back out of service. Clearly for my taste and service the tubed output is much preferred.

The tubed output from a modded 685, being a text book grounded cathode, has a output impedance of @ 21K with a 12AX7 and @ 6K with a 12AU7, hence the benefit of adding the Z box, OP impedance @ 600 ohms.

Yes! When I lost my Audio Alchemy Digital Drive System (DDS-III) Transport 28 months ago it was a very sad day. IT of course, was designed/voiced to process/play in concert with DTI-Pro & 3.0 DAC.....an that it did. Analog sounding to a degree... .

The DTS-III died after 9.5 years of service. I found out real quick what and important part a transport plays in a system. With all do repect to my Pioneer DVD Player outputing the binary code for the last 28 months....it is no DDS-III. The system would still image well; but I lost the depth, ambience of venue, tighter low end and some edge crept back in to the system (just a little less musical / back to hifi sounding on some discs).

Decfest was a blast and I bought a pair of Parker Crusaders which now alternate with my Polk LS90's. Two very different speakers that both will benefit greatly from the ZBox. I bought the Parkers in Nov/05....now the budget allowed to get the Zbox.

I got to hear the ZBox at Decfest and I new, to get back to what I had with the DDS-III (or better).....the Zbox needed to join my family of magic boxes. My DAC outputs a little over 3 volts (which is adjustable too) and it will be nice to attenuate my DAC (it has a volume control with remote/albeit in the digital domain) with Zbox attenuater and the Select wide open.

It is nice not to have to go down the path of a single box player/modded or transport/modded at three times + the price of a ZBox. I love my Audio Alchemy gear/and as long as it holds up=in comes the ZBox.....to make the most of things again. All due respect to the new Rega Apollo; but the addition of the ZBox at 60% less in my mix should put the whole musicallity back in my room. Decfest was well worth the trip to hear the ZBox alone....not to mention all of whom I met.

Will do Karl. I have some different interconnects to roll with it (Kimber KCAG, Kimber Silver Streak & Hero....with my 1030). I will read again and ask for some advice on tubes to roll from you guys....great informative posts on the ZBox here for sure/thanks. I think it will be the right fit too, as you say, and I agree; making CD playback more tolerable thus musical. It ain't vinyl....but we can massage it and make it more involving.

Dec685 (the tubed out is way beyond the stock outs) > zbox > CSP > se84cs.

It's a lot of stages and ic's, I know, but it makes cd's ever so much more tolerable, which are between C- and B- anyway (so, what's to lose?). Not as nice as vinyl, but not so annoying with less ear fatigue.

The volume on the zen is backed off about 10%, which is where it sounds the best in my system. The zbox is turned up pretty high and the major volume control in my system is the CSP.

What makes the zbox work for me is a BB 12au7, by a long shot. IC's and other tweaks make a difference, but the difference in the valves is really the biggest thing.

So, Sam, is there a revamp of the zbox you know about? I hope you will report some on differences you get with the Schottke diodes you installed in yours (or maybe I missed a post somewhere).

[quote author=ado420 link=1119443490/30#42 date=1144860341]the 60 Hz wouldn't bother me so much if it wasn't for the 2nd harmonic being many times louder (120 Hz). That makes sense tho based on what I know of multi-phase AC transformers. [/quote]

In the zbox, the power supply hum is 120Hz because of full wave rectification

yes, thank you, I was already well aware. But I think the reason is the problem as well.

ya, full wave rectification doubles the fundemental, and since most devices use full wave rectification, you'll always get 120 Hz and its' harmonics being problematic. But then you get a device that is quite microphonic, like tubes, and it'll constantly oscillate at said harmonics and introduce its' own into the mix. It tends to get messy with all the PS's I have in my house.

It's sad when you stand between two motors and can hear the phase shift between the two harmonics. It can even create a new fundemental depending on where you stand. I think that's called the missing fundemental, it's what SRS uses in their TruBass thingy. Comes from pipe organ makers, trying to get lower octaves without the cost and structural problems they introduce.

Well I got my Zbox a couple of months ago. I love what it has done for my CD player. I just don't know why it shipped with a JJ 12ax7. To me that is one bad sounding tube. It may be because it is new and hasn't broke in yet. But I also have a new EH 12au7 that blows it away. The JJ is just to much distortion.But after much rolling the 2 tubes I mainly use are the NOS RCA 12au7 black plates and the clear tops. The black plates are best for new recordings. Very precise and clean, great bass.The clear tops are my best for old recordings. Those days when it's going to be Frank, Ella and the likes, it's the clear tops for sure. The thing about the cleartops for new recordings they are a little laid back. Stings and vocals are back with the band, instead of slightly forward where I think they should be. But with old recordings where horns, vocals and strings seem to be too forward, the cleartops tame them down where they should be. Which also gives the illusion of more bass which is need on older recordings. Just my 2¢

The new production Tung Sol 12ax7 is a really nice sounding tube... I use it in my Taboo and it sounds quite nice, only using a cd player as source with output of 2volts so the Tung Sol works excellent for me... http://thetubestore.com/tungsol12ax7.html Dave

Well I got my Zbox a couple of months ago. I love what it has done for my CD player. I just don't know why it shipped with a JJ 12ax7. To me that is one bad sounding tube. It may be because it is new and hasn't broke in yet. But I also have a new EH 12au7 that blows it away. The JJ is just to much distortion.But after much rolling the 2 tubes I mainly use are the NOS RCA 12au7 black plates and the clear tops. The black plates are best for new recordings. Very precise and clean, great bass.The clear tops are my best for old recordings. Those days when it's going to be Frank, Ella and the likes, it's the clear tops for sure. The thing about the cleartops for new recordings they are a little laid back. Stings and vocals are back with the band, instead of slightly forward where I think they should be. But with old recordings where horns, vocals and strings seem to be too forward, the cleartops tame them down where they should be. Which also gives the illusion of more bass which is need on older recordings. Just my 2¢

Jim, I think the 12AX7 just has too much gain for the ZBox, and really I would bet Steve meant to send you a 12AU7 or 12AT7.

I have found that 12AU7s work best for me in both the ZBox and the DEC685. So if you prefer the 12AU7 I don't doubt that it is what you should be using.

Would a two input, switchable, ZBox be possible without losing the magic>? That would be an IDEAL component for me. . . I could buy a ZCD and use the ZBox for both that and my Sony flagship Blu-Ray player, and run it into the CSP2. The other input on the CSP2 could be used for the TV audio out. . . .My system would be just what I want I bet!

Would a two input, switchable, ZBox be possible without losing the magic>? That would be an IDEAL component for me. . . I could buy a ZCD and use the ZBox for both that and my Sony flagship Blu-Ray player, and run it into the CSP2. The other input on the CSP2 could be used for the TV audio out. . . .My system would be just what I want I bet!

It could be done sure. I would probably recommend (especially since you already have a CSP2) that you listen to the ZCD both with and without a ZBOX to determine if it's really worth the trouble first.